Exposure apparatus, device manufacturing method, semiconductor manufacturing plant and method of maintaining exposure apparatus

ABSTRACT

An exposure apparatus includes a plurality of purge spaces delimited along the optical path between the laser light source and the substrate by housings the boundary members of which are invisible to the exposing light, and pressure regulating unit for exercising control in such a manner that the pressure within each purge space attains a predetermined value. In the exposure apparatus that is purged in sections, therefore, it is possible to reduce the amount of deformation of the end faces between mutually adjacent purge spaces, e.g., the end face of a projection optics unit.

FIELD OF THE INVENTION

[0001] This invention relates to an exposure apparatus, a devicemanufacturing method for manufacturing semiconductor devices, asemiconductor manufacturing plant in which the exposure apparatus hasbeen installed, and a method of maintaining the exposure apparatus. Moreparticularly, the invention relates to an exposure apparatus in whichthe optic axis of exposing light is divided into a plurality of spacesand the spaces are purged independently.

BACKGROUND OF THE INVENTION

[0002] In the manufacture of semiconductor devices in recent years,there is an ever increasing tendency to use shorter wavelengths for theexposing light source in the associated exposure apparatus. The reasonfor this is that using shorter wavelengths raises the resolution of theprojection exposure system and makes it possible to expose finerpatterns. For example, since an F₂ excimer laser has a short wavelengthof 157 nm, application of this laser to exposure apparatus isproceeding. However, since exposing light produced by an F₂ excimerlaser is absorbed in an O₂ or H₂O environment, the space traversed bythe exposing light must be purged using an inert gas.

[0003] Methods adopted to deal with this include a method of placing theoverall exposure apparatus inside a tightly sealed chamber and a methodof dividing the apparatus into several sections and purging eachsection.

[0004] In a case where the exposure apparatus is divided and purged,however, each individual section is controlled independently. A problemwhich arises is that a pressure difference develops between the sectionsand leads to deformation at the boundaries of these sections. Sincethese boundary areas consist of members that are transparent to theexposing light, even minute deformation of these members worsens theaberration of the exposing light.

SUMMARY OF THE INVENTION

[0005] The present invention has been proposed to solve the foregoingproblems and an object thereof is to provide an exposure apparatus thatis purged in sections, wherein the apparatus is so adapted as to reducethe amount of deformation of an end face, such as the end face of aprojection optics system, between purged spaces in the apparatus.

[0006] According to a first aspect of the present invention, theforegoing object is attained by providing an exposure apparatus byexposing light emitted from a laser light source such as an F₂ excimerlaser, comprising: a plurality of housings provided adjacent one anotherin order to cover at least part of the optical path of the exposinglight; exposing-light-transparent members provided at boundaries of theadjacent housings; a gas supplier which supplies the interior of eachhousing with a purging gas; pressure sensors which sense pressuresinside respective ones of the housings; and a control unit whichcontrols the gas supplier on the basis of outputs from the pressuresensors in such a manner that pressures within the respective housingswill attain respective ones of predetermined pressures.

[0007] According to a second aspect of the present invention, theforegoing object is attained by providing an exposure apparatus byexposing light emitted from a laser light source such as an F₂ excimerlaser, comprising: a plurality of housings provided adjacent one anotherin order to cover at least part of the optical path of the exposinglight; exposing-light transparent members provided at boundaries of theadjacent housings; a gas supplier which supplies the interior of eachhousing with a purging gas; differential-pressure sensors which sensedifferences in pressure between adjacent ones of the housings; and acontrol unit which controls the gas supplier on the basis of outputsfrom the differential-pressure sensor in such a manner that pressureswithin the respective housings will attain respective ones ofpredetermined pressures.

[0008] In a preferred embodiment, an unit which regulates pressureincludes pressure sensors provided in respective ones of the housings ordifferential-pressure sensors provided between the plurality of housings(e.g., directly in the partition walls of adjacent purge spaces), andair conditioners capable of introducing inert gas to respective ones ofthe housings and exhausting gas from the interior of respective ones ofthe housings. The air conditioners are operated while adjusting, e.g.,the ratio of amount of inert gas introduced to the amount of exhaust inaccordance with measurement values from the pressure sensors ordifferential-pressure sensors in such a manner that interiors of thepurge spaces attain predetermined pressures.

[0009] The plurality of spaces can be classified broadly into an opticsspace containing members of the optical system, and a drive spacecontaining driving members. The optics space can be divided into aguiding optics space for introducing laser light into the apparatus, anilluminating optics space for illuminating a reticle with exposinglight, and a projection optics space for projecting the reticle patternonto a substrate. The drive space can be divided into a reticle-stagespace containing a reticle stage on which the reticle is mounted, asubstrate-stage space containing a substrate stage on which thesubstrate is mounted, and a masking-blade space containing a maskingblade. By thus finely partitioning the exposure space, the purge spacescan be reduced in size. This makes it possible to reduce the amount ofinert gas consumed and to lower operating cost greatly.

[0010] The inert gas should be one that is inert to reticles and wafers.Examples of inert gas that can be used are nitrogen gas and helium, etc.Using a combination of inert gases is desirable, such as adopting ahelium atmosphere for the optics space and a nitrogen-gas atmosphere forthe drive space.

[0011] Ordinarily, pressure inside the projection optics space iscontrolled so as to be held constant in order that this internalpressure will not fluctuate with a change in atmospheric pressure.Accordingly, the pressure within each purge space preferably isregulated using the internal pressure of the projection optics space asa reference.

[0012] Further, a purge space requiring a high level of cleanliness, asin the case of the projection optics space, should be held at a pressureslightly higher than that of the other purge spaces. This is effectivein holding cleanliness-sensitive spaces at a high level of cleanliness.In this case, however, there is the danger that optical performance willbe affected if the boundary members are deformed. It is thereforenecessary to exercise control in such a manner that the differentialpressure of neighboring purge spaces will fall within predeterminedlimits.

[0013] The range of differential pressures is decided in accordance withamount of deformation of a boundary member (optical element) withrespect to a difference in pressure, and amount of change in opticalperformance, which is found from the amount of deformation. As oneexample, assume that a certain projection optics boundary consists of aflat plate of SiO₂ having a thickness of 3 mm. In such case the pressuredifference should be on the order of 0.05 to 5 hPa, and preferably onthe order of 0.5 hPa. It cannot be said unqualifiedly that the value of0.5 hPa is optimum because the optimum value differs depending upon thedesign of the optical system. In the case of this particular example, isshould be so arranged that the pressures for a wafer stage (W), reticlestage (R), illuminating system (S), guiding optics (T), laser (L) andmasking blade (MB) be as follows with respect to the pressure of theprojection optics (P) (where the unit of pressure is hPa):

[0014] P−0.5<W<P−0.1

[0015] P−0.5<R<P−0.1

[0016] R<S<R+0.5

[0017] S−0.5<T<S−0.1

[0018] T−0.5<L<S

[0019] P−0.5<MB<P−0.1

[0020] Furthermore, the exposure apparatus according to the presentinvention is provided with a display, a network interface and a computerfor executing network software, whereby it is possible to transmitexposure-apparatus maintenance information by data communication via acomputer network.

[0021] The network software provides the display with a user interfacefor accessing a maintenance database, which is connected to an externalnetwork of a plant at which said exposure apparatus has been installed,the database being provided by a vendor or user of the exposureapparatus. This make it possible to obtain

[0022] A device manufacturing method according to the present inventioncomprises steps of placing a group of manufacturing equipment forvarious processes, inclusive of the above-described exposure apparatus,in a plant for manufacturing semiconductor devices, and manufacturing asemiconductor device by a plurality of processes using this group ofmanufacturing equipment.

[0023] Furthermore, the method of manufacturing semiconductor devicesmay further include the steps of interconnecting the group ofmanufacturing equipment by a local-area network, and communicating, bydata communication, information relating to at least one item ofmanufacturing equipment in the group thereof between the local-areanetwork and an external network outside the semiconductor manufacturingplant.

[0024] Further, an arrangement may be adopted in which maintenanceinformation for the manufacturing equipment is obtained by accessing, bydata communication via the external network, a database provided by avendor or user of exposure apparatus, or production management isperformed by data communication with a semiconductor manufacturing plantother than the first-mentioned plant via the external network.

[0025] A semiconductor manufacturing plant according to the presentinvention comprises: a group of items of manufacturing equipment forvarious processes, inclusive of the above-described exposure apparatusaccording to the present invention; a local-area network whichinterconnects the group of items of manufacturing equipment; and agateway which makes it possible for the local-area network to access anexternal network outside the plant; wherein information relating to atleast one item of manufacturing equipment among the group thereof iscapable of being communicated by data communication.

[0026] A method of maintaining an exposure apparatus according to thepresent invention comprises the steps of: providing, by a vendor or userof the exposure apparatus, a maintenance database connected to anexternal network of a semiconductor manufacturing plant; allowing themaintenance database to be accessed from inside the semiconductormanufacturing plant via the external network; and transmittingmaintenance information, which has been stored in the maintenancedatabase, to the semiconductor manufacturing plant via the externalnetwork.

[0027] Other features and advantages of the present invention will beapparent from the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

[0029]FIG. 1 is a sectional schematic view illustrating an example of asemiconductor exposure apparatus in which an F₂ excimer laser serves asthe light source;

[0030]FIG. 2 is a sectional schematic view useful in describingregulation of pressure in the semiconductor exposure apparatus;

[0031]FIG. 3 is a sectional schematic view illustrating another exampleof a semiconductor exposure apparatus in which an F₂ excimer laserserves as the light source;

[0032]FIG. 4 is a conceptual view showing a semiconductor deviceproduction system as seen from a certain angle;

[0033]FIG. 5 is a conceptual view showing a semiconductor deviceproduction system as seen from another angle;

[0034]FIG. 6 shows a specific example of a user interface;

[0035]FIG. 7 is a diagram useful in describing the flow of a devicemanufacturing process; and

[0036]FIG. 8 is a diagram useful in describing a wafer process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Preferred embodiments of the present invention will now bedescribed in detail in accordance with the accompanying drawings.

[0038] (First Embodiment)

[0039]FIG. 1 is a sectional schematic view illustrating an example of asemiconductor exposure apparatus according to the present invention inwhich an F₂ excimer laser serves as the light source.

[0040] Shown in FIG. 1 are a reticle stage 1 on which has been mounted areticle bearing a pattern, a projecting optics unit (lens barrel) 2 forprojecting the pattern on the reticle onto a wafer (substrate), and awafer stage 3 on which the waver has been mounted for driving the waferin X, Y, Z, θ and tilt directions.

[0041] The apparatus further includes an illuminating optics unit 4 forirradiating the reticle with illuminating light; a guiding optics unit 5for guiding exposing light from the light source to the illuminatingoptics unit 4; an F₂ laser unit 6 serving as the light source; a maskingplate 7 for masking the exposing light in such a manner that an areaother than the pattern on the reticle will not be illuminated; andhousings 8, 9 enclosing the reticle stage 1 and wafer stage 3 to coverthe optic axis of the exposing light.

[0042] The apparatus further includes a helium air conditioner 10 foradjusting the interiors of the lens barrel 2 and illuminating opticsunit 4 to a prescribed helium atmosphere; nitrogen-gas air conditioners11 and 12 for adjusting the interiors of the housings 8 and 9,respectively, to a prescribed nitrogen-gas atmosphere; a reticle loadinglock 13 and a wafer loading lock 14 used when a reticle and a wafer arecarried into the housings 8 and 9, respectively; a reticle hand 15 and awafer hand 16 for transporting a reticle and a wafer, respectively; areticle alignment mark 17 used when the reticle position is adjusted; areticle storage bin 18 for storing a plurality of reticles inside thehousing 8; and an prealignment unit 19 for wafer prealignment. Thehelium air conditioner 10 and nitrogen-gas air conditioners 11, 12function as gas suppliers for supplying these gases, which are inertwith the reticle and wafer.

[0043]FIG. 2 is a sectional schematic view useful in describingadjustment of pressure in each purge space of the exposure apparatusaccording to this embodiment. The apparatus includes a feed pipe 22 afor feeding helium gas serving as a purging gas from the helium airconditioner 10 to an illuminating optics space 27 inside theilluminating optics unit 4; a feed pipe 22 b for feeding nitrogen gasserving as a purging gas from the nitrogen-gas air conditioner 11 to areticle-stage space 28 enclosed by the housing 8; a feed pipe 22 c forfeeding helium gas serving as a purging gas from the helium airconditioner 10 to a lens-barrel space 29 inside the projecting opticsunit 2; and a feed pipe 22 d for feeding nitrogen gas serving as apurging gas from the nitrogen-gas air conditioner 12 to asubstrate-stage space 30 enclosed by the housing 9.

[0044] The apparatus further includes an exhaust pipe 23 a forexhausting the purging gas from the illuminating optics space 27 to thehelium air conditioner 10; an exhaust pipe 23 b for exhausting thepurging gas from the reticle-stage space 28 to the nitrogen-gas airconditioner 11; an exhaust pipe 23 c for exhausting the purging gas fromthe lens-barrel space 29 to the helium air conditioner 10; and anexhaust pipe 23 d for exhausting the purging gas from thesubstrate-stage space 30 to the nitrogen-gas air conditioner 12.

[0045] The apparatus further includes differential-pressure gauges(differential-pressure sensors) 24 a, 24 b and 24 c for measuring thedifferential pressures between neighboring purge spaces. Specifically,the differential-pressure sensor 24 a measures the differential pressurebetween the illuminating optics space 27 and the reticle-stage space 28,the differential-pressure sensor 24 b measures the differential pressurebetween the reticle-stage space 28 and the lens-barrel space 29, and thedifferential-pressure sensor 24 c measures the differential pressurebetween the lens-barrel space 29 and the substrate-stage space 30. Thesedifferential-pressure gauges are provided directly in the partitioningwalls between the neighboring purge spaces. A pressure gauge (pressuresensor) 25 a measures the internal pressure of the illuminating opticsspace 27, a pressure gauge 25 b measures the internal pressure of thereticle-stage space 28, a pressure gauge 25 c measures the internalpressure of the lens-barrel space 29, and a pressure gauge 25 d measuresthe internal pressure of the substrate-stage space 30. The apparatus isprovided with flat plates (exposing-light-transparent members) 26 a, 26b, 26 c of SiO₂ having a thickness of 3 mm. These plates are disposed inthe optical path of the exposing light and are adapted in such a mannerthat the outer walls of the respective housings will not block theexposing light. The flat plates 26 a to 26 c may consist of a fluorinecompound such as calcium fluoride or magnesium fluoride.

[0046] In this specification, the spaces such as the illuminating opticsspace 27 and lens-barrel space 29 that include optical members shall bereferred to as optics spaces, and the spaces such as the reticle-stagespace 28, substrate-stage space 30 and masking-blade space that includedrive members shall be referred to as drive spaces. The reticle-stagespace 28 signifies a space that contains the reticle stage 1, thesubstrate-stage space 30 signifies a space that contains the wafer stage3, and the masking-blade space specifies a space that contains themasking plate 7.

[0047] Control of each purge space according to this embodiment will nowbe described with reference to FIGS. 1 and 2.

[0048] This apparatus is controlled in such a manner that the pressureinside the lens-barrel space 29 is held constant so as not to be changedby atmospheric pressure. Control of the lens-barrel space 29 is carriedout by measuring internal pressure of the lens barrel 2 by the pressuregauge 25 c and adjusting the ratio of amount of helium introduced by thefeed pipe 22 c from the helium air conditioner 10 to the amount ofexhaust by the feed pipe 23 c using control valves (not shown) basedupon the measured value of internal pressure.

[0049] The control valves, which are provided in the air conditioners10, 11 and 12, each function to control the ratio of amount of purginggas supplied to amount of exhaust, thereby regulating the pressureswithin the purge spaces 27 to 30. At this time whichever of the purgespaces requires a high level of cleanliness is held at a pressure higherthan that of the neighboring purge spaces. The control valves arecontrolled by a control unit, which is not shown. By way of example, thecontrol unit controls the control valves based upon the outputs of thepressure gauges 24 a to 24 d.

[0050] The reticle-stage space 28 has its internal pressure regulatedusing control valves (not shown) to adjust the ratio of amount of heliumintroduced by the feed pipe 22 b from the nitrogen-gas air conditioner11 to the amount of exhaust by the feed pipe 23 c in such a manner thatthe differential pressure between the reticle-stage space 28 and thelens-barrel space 29 falls within a predetermined range, with thepressure regulation being performed based upon the value from thedifferential-pressure sensor 24 b provided in the partitioning wallbetween the reticle-stage space 28 and the lens-barrel space 29.Similarly, the substrate-stage space 30 has its internal pressureregulated using control valves (not shown) to adjust the ratio of amountof nitrogen gas introduced by the feed pipe 22 d from the nitrogen-gasair conditioner 11 to the amount of exhaust by the feed pipe 23 d insuch a manner that the differential pressure between the substrate-stagespace 30 and the lens-barrel space 29 falls within a predeterminedrange, with the pressure regulation being performed based upon the valuefrom the differential-pressure sensor 24 c provided in the partitioningwall between the substrate-stage space 30 and the lens-barrel space 29.

[0051] The illuminating optics space 27 has its internal pressureregulated using control valves (not shown) to adjust the ratio of amountof helium introduced by the feed pipe 22 a from the helium airconditioner 10 to the amount of exhaust by the feed pipe 23 a in such amanner that the differential pressure between the illuminating opticsspace 27 and reticle-stage space 28 falls within a predetermined range,with the pressure regulation being performed based upon the value fromthe differential-pressure sensor 24 a provided in the partitioning wallbetween the illuminating optics space 27 and the reticle-stage space 28.Similarly, the space for the masking plate 7 and the space for theguiding optics unit 5 are regulated in such a manner that thedifferential pressures between the respective neighboring purge spacesare rendered constant.

[0052] The pressure within each housing is controlled in such a mannerthat the amount of deformation of members caused by a difference inpressure with respect to the pressure within the neighboring housingwill fall within a range of pressures that will not have a significanteffect upon optical performance. More specifically, the range ofdifferential pressures is decided in accordance with amount ofdeformation of each of the boundary members 26 a, 26 b, 26 c, which areoptical elements, with respect to a difference in pressure, and amountof change in optical performance, which is found from the amount ofdeformation. The pressure difference is adjusted to 0.5 hPa.

[0053] In this embodiment, the pressures of a wafer stage (W), reticlestage (R), illuminating system (S), guiding optics (T), laser (L) andmasking blade (MB) are controlled so as to fall within the followingranges with respect to the pressure of the projection optics (P) (wherethe unit of pressure is hPa):

[0054] P−0.5<W<P−0.1

[0055] P−0.5<R<P−0.1

[0056] R<S<R+0.5

[0057] S−0.5<T<S−0.1

[0058] T−0.5<L<S

[0059] P−0.5<MB<P−0.1

[0060] In accordance with this embodiment, the pressures within thelens-barrel space 29 and illuminating optics space 27 can be held abovethose of the neighboring drive spaces by a minute range at all timeseven if the internal pressures of the drive spaces fluctuate owing toloading and unloading of wafers and reticles.

[0061] Further, since a fluctuation in the internal pressure of eachpurge space can be held to a minimum, a fluctuation in the amount ofdeformation of each of the boundary members 26 a to 26 c can be held toa minimum at all times. Furthermore, since the purge spaces such as thedrive spaces are reduced in size as a result of partitioning, the amountof inert gas used can be reduced, thereby making it possible to operatethe apparatus inexpensively.

[0062] Thus, in accordance with this embodiment, the amount ofdeformation of the end face of a projecting optics unit is reduced in anexposure apparatus that is purged in sections. Further, the levels ofcleanliness of the partitioned sections can be ranked and the sectionmost sensitive of cleanliness can be held at the highest level ofcleanliness.

[0063] Though one lens-barrel space 29, which is a space within theprojecting optics unit 2, is provided in this embodiment, the inventionis not limited to this arrangement. For example, the space within theprojecting optics unit 2 may be divided into a plurality of spaces andthese may be purged. In such case each space within the projectingoptics unit 2 would be provided with a pressure gauge and pressuregauges would be provided for measuring the differential pressuresbetween the neighboring spaces. It should be noted that if the spacewithin the projecting optics unit 2 is divided into a plurality ofspaces, the lenses of the projecting optics unit perform the role of thepartitioning walls between the spaces. Further, in a case where amagnification correction lens in the projecting optics unit 2 moves, theinternal space would be divided into a space that includes themagnification correction lens and spaces that include the other lenses.

[0064] [Second Embodiment]

[0065] In this embodiment, each pressure range is decided in advance insuch a manner that the differential pressures between neighboring purgespaces will be rendered constant. Accordingly, the internal pressures ofthe purge spaces are regulated by the pressure gauges 24 a to 24 d. Thisembodiment is similar to the first embodiment in other respects.

[0066] In accordance with this embodiment, the range of pressures ineach purge space can be held constant. By setting the area offluctuation to a desired range, the optics space can be kept clean atall times in a manner similar to that of the first embodiment. Further,since the pressure within the illuminating optics unit 4 will notfluctuate in association with any fluctuation in pressure withinneighboring purge spaces (e.g., the reticle-stage space 28, the spacecontaining the masking plate 7, etc.), there is no danger that opticalperformance of the illuminating optics unit 4 will change. Further, asin the first embodiment, a boundary member that is transparent toexposing light is provided between the adjacent housings that define thepurge spaces.

[0067] [Third Embodiment]

[0068]FIG. 3 is a sectional schematic view illustrating another exampleof a semiconductor exposure apparatus in which an F₂ excimer laserserves as the light source according to the present invention.

[0069] As shown in FIG. 3, a housing 20 encompasses the entire exposureapparatus. The lens barrel 2 and illuminating optics unit 4 are providedinside the housing 20. An air conditioner 21 establishes a nitrogen-gasatmosphere within the entirety of the housing 20. In this embodiment,the internal spaces of the lens barrel 2 and illuminating optics unit 4are isolated from the internal space (a drive space 31) of the housing20 and are regulated independently to establish a helium atmosphere ineach.

[0070] The method of controlling the pressures within the purge spacesof this embodiment is similar to that of the first and secondembodiments. However, since the interior of the drive space 3 iscontrolled collectively, the apparatus can be constructed more simplyand at lower cost.

[0071] (Embodiment of Semiconductor Production System)

[0072] Described next will be an example of a system for producingsemiconductor devices (semiconductor chips such as IC and LSI chips,liquid crystal panels, CCDs, thin-film magnetic heads and micromachines,etc.). This system utilizes a computer network outside the semiconductormanufacturing plant to provide troubleshooting and regular maintenanceof manufacturing equipment installed at the manufacturing plant and tofurnish maintenance service such as the provision of software.

[0073]FIG. 4 illustrates the overall system as seen from a certainangle. The system includes the business office 101 of the vendor(equipment supplier) that provides the equipment for manufacturingsemiconductor devices. Semiconductor manufacturing equipment for variousprocesses used in a semiconductor manufacturing plant is assumed to bethe manufacturing equipment. Examples of the equipment are pre-treatmentequipment (lithographic equipment such as exposure equipment, resisttreatment equipment and etching equipment, heat treatment equipment,thin-film equipment and smoothing equipment, etc.) and post-treatmentequipment (assembly equipment and inspection equipment, etc.). Thebusiness office 101 includes a host management system 108 for providinga manufacturing-equipment maintenance database, a plurality of controlterminal computers 110, and a local-area network (LAN) 109 forconnecting these components into an intranet. The host management system108 has a gateway for connecting the LAN 109 to the Internet 105, whichis a network external to the business office 101, and a securityfunction for limiting access from the outside.

[0074] Numerals 102 to 104 denote manufacturing plants of semiconductormakers which are the users of the manufacturing equipment. Themanufacturing plants 102 to 104 may be plants belonging to makers thatdiffer from one another or plants belonging to the same maker (e.g.,pre-treatment plants and post-treatment plants, etc.). Each of theplants 102 to 104 is provided with a plurality of pieces ofmanufacturing equipment 106, a local-area network (LAN) 111 whichconnects these pieces of equipment to construct an intranet, and a hostmanagement system 107 serving as a monitoring unit for monitoring thestatus of operation of each piece of manufacturing equipment 106. Thehost management system 107 provided at each of the plants 102 to 104 hasa gateway for connecting the LAN 111 in each plant to the Internet 105serving as the external network of the plants. As a result, it ispossible for the LAN of each plant to access the host management system108 on the side of the vendor 101 via the Internet 105. By virtue of thesecurity function of the host management system 108, users allowed toaccess the host management system 108 are limited.

[0075] More specifically, status information (e.g., the condition ofmanufacturing equipment that has malfunctioned), which indicates thestatus of operation of each piece of manufacturing equipment 106, can bereported from the plant side to the vendor side. In addition,information in response to such notification (e.g., informationspecifying how to troubleshoot the problem, troubleshooting software anddata, etc.), as well as the latest software and maintenance informationsuch as help information, can be acquired from the vendor side. Acommunication protocol (TCP/IP), which is used generally over theInternet, is employed for data communication between the plants 102˜104and the vendor 101 and for data communication over the LAN 111 withineach plant. Instead of utilizing the Internet as the external network ofa plant, it is also possible to utilize a highly secure leased-linenetwork (ISDN, etc.) that cannot be accessed by a third party.

[0076] Further, the host management system is not limited to thatprovided by a vendor, for an arrangement may be adopted in which theuser constructs a database, places it on an external network and allowsthe database to be accessed from a number of plants that belong to theuser.

[0077]FIG. 5 is a conceptual view illustrating the overall system ofthis embodiment as seen from an angle different from that depicted inFIG. 4. In the earlier example, a plurality of user plants each havingmanufacturing equipment are connected by an external network to themanagement system of the vendor that provided the manufacturingequipment, and information concerning the production management of eachplant and information concerning at least one piece of manufacturingequipment is communicated by data communication via the externalnetwork. In the example of FIG. 5, on the other hand, a plant havingmanufacturing equipment provided by a plurality of vendors is connectedby an outside network to management systems of respective ones of thevendors of these plurality of pieces of manufacturing equipment, andmaintenance information for each piece of manufacturing equipment iscommunicated by data communication. This system includes a manufacturingplant 201 of the user of manufacturing equipment (the maker ofsemiconductor devices). The manufacturing line of this plant includesmanufacturing equipment for implementing a variety of processes.Examples of such equipment are exposure equipment 202, resist treatmentequipment 203 and thin-film treatment equipment 204.

[0078] Though only one manufacturing plant 201 is shown in FIG. 5, inactuality a plurality of these plants are networked in the same manner.The pieces of equipment in the plant are interconnected by a LAN 206 toconstruct an intranet and the operation of the manufacturing line ismanaged by a host management system 205. The business offices of vendors(equipment suppliers) such as an exposure equipment maker 210, resisttreatment equipment maker 220 and thin-film treatment equipment maker230 have host management systems 211, 221, 231, respectively, for remotemaintenance of the equipment they have supplied. These have maintenancedatabases and gateways to the outside network, as described earlier. Thehost management system 205 for managing each piece of equipment in themanufacturing plant of the user is connected to the management systems211, 221, 231 of the vendors of these pieces of equipment by theInternet or leased-line network serving as an external network 200. Ifany of the series of equipment in the manufacturing line malfunctions,the line ceases operating. However, this can be dealt with rapidly byreceiving remote maintenance from the vendor of the faulty equipment viathe Internet 200, thereby making it possible to minimize line downtime.

[0079] Each piece of manufacturing equipment installed in thesemiconductor manufacturing plant has a display, a network interface anda computer for executing network-access software and equipment operatingsoftware stored in a storage device.

[0080] The storage device can be an internal memory or hard disk or anetwork file server. The software for network access includes aspecial-purpose or general-purpose Web browser and presents a userinterface, which has a screen of the kind shown by way of example inFIG. 6, on the display. The operator managing the manufacturingequipment at each plant enters information at the input items on thescreen while observing the screen. The information includes model (401)of the manufacturing equipment, its serial number (402), subject matter(403) of the problem, its date of occurrence (404), degree of urgency(405), the particular condition (406), countermeasure method (407) andprogress report (408). The entered information is transmitted to themaintenance database via the Internet. The resulting appropriatemaintenance information is sent back from the maintenance database andis presented on the display screen. The user interface provided by theWeb browser implements hyperlink functions (410 to 412) as illustratedand enables the operator to access more detailed information for eachitem, to extract the latest version of software, which is used for themanufacturing equipment, from a software library provided by the vender,and to acquire an operating guide (help information) for reference bythe plant operator.

[0081] A process for manufacturing a semiconductor device utilizing theproduction system set forth above will now be described. FIG. 7illustrates the overall flow of a process for manufacturingsemiconductor devices. The circuit for the device is designed at step 1(circuit design). A mask on which the designed circuit pattern has beenformed is fabricated at step 2 (mask fabrication). Meanwhile, a wafer ismanufactured using a material such as silicon or glass at step 3 (wafermanufacture). The actual circuit is formed on the wafer by lithography,using the mask and wafer that have been prepared, at step 4 (waferprocess), which is also referred to as “pre-treatment”. A semiconductorchip is obtained, using the wafer fabricated at step 4, at step 5(assembly), which is also referred to as “posttreatment”. This stepincludes steps such as actual assembly (dicing and bonding) andpackaging (chip encapsulation). The semiconductor device fabricated atstep 5 is subjected to inspections such as an operation verificationtest and durability test at step 6 (inspection). The semiconductordevice is completed through these steps and then is shipped (step 7).

[0082] The pre- and post-treatments are performed at separatespecial-purpose plants. Maintenance is carried out on a per-plant basisby the above-described remote maintenance system. Further, informationfor production management and equipment maintenance is communicated bydata communication between the pre- and post-treatment plants via theInternet or leased-line network.

[0083]FIG. 8 is a flowchart illustrating the detailed flow of the waferprocess mentioned above. The surface of the wafer is oxidized at step 11(oxidation). An insulating film is formed on the wafer surface at step12 (CVD), electrodes are formed on the wafer by vapor deposition at step13 (electrode formation), and ions are implanted in the wafer at step 14(ion implantation). The wafer is coated with a photoresist at step 15(resist treatment), the wafer is exposed to the circuit pattern of themask to print the pattern onto the wafer by the above-described exposureapparatus at step 16 (exposure), and the exposed wafer is developed atstep 17 (development). Portions other than the developed photoresist areetched away at step 18 (etching), and unnecessary resist left afteretching is performed is removed at step 19 (resist removal). Multiplecircuit patterns are formed on the wafer by implementing these stepsrepeatedly. Since the manufacturing equipment used at each step ismaintained by the remote maintenance system described above,malfunctions can be prevented and quick recovery is possible if amalfunction should happen to occur. As a result, the productivity ofsemiconductor device manufacture can be improved over the prior art.

[0084] Thus, with the exposure apparatus according to the presentinvention, a plurality of purge spaces within the exposure apparatus arecontrolled so as to attain respective ones of predetermined pressures,thereby making it possible to reduce the deformation of boundary membersbetween the purge spaces.

[0085] Further, with the exposure apparatus according to the presentinvention, the differential pressure between neighboring purge spaceswithin the exposure apparatus is controlled, thereby making it possibleto reduce the deformation of boundary members between the purge spaces.

[0086] As many apparently widely different embodiments of the presentinvention can be made without departing from the spirit and scopethereof, it is to be understood that the invention is not limited to thespecific embodiments thereof except as defined in the appended claims.

What is claimed is:
 1. An exposure apparatus comprising: a plurality ofhousings, said housings are provided adjacently, which cover at leastpart of an optical path of exposing light; members transparent toexposing light provided at boundaries of the adjacent housings; a gassupplier which supplies the interior of each housing with a purging gas;pressure sensors which sense pressures inside respective ones of saidhousings; and a control unit which controls said gas supplier on thebasis of outputs from said pressure sensors in such a manner thatpressures within the respective housings will attain respective ones ofpredetermined pressures.
 2. An exposure apparatus comprising: aplurality of housings, said housings are provided adjacently, whichcover at least part of an optical path of exposing light; memberstransparent to exposing light provided at boundaries of the adjacenthousings; a gas supplier which supplies the interior of each housingwith a purging gas; differential-pressure sensors which sensedifferences in pressure between adjacent ones of said housings; and acontrol unit which controls said gas supplier on the basis of outputsfrom said differential-pressure sensors in such a manner that pressureswithin the respective housings will attain respective ones ofpredetermined pressures.
 3. The apparatus according to claim 1 , whereinsaid gas supplier includes air conditioners capable of supplying apurging gas to respective ones of said housings and of exhausting gasfrom the interior of respective ones of said housings; said airconditioners being operated in such a manner that measured valuesprovided by said pressure sensors attain respective ones of thepredetermined pressures.
 4. The apparatus according to claim 2 , whereinsaid gas supplier includes air conditioners capable of supplying apurging gas to respective ones of said housings and of exhausting gasfrom the interior of respective ones of said housings; said airconditioners being operated in such a manner that measured valuesprovided by said differential-pressure sensors attain respective ones ofthe predetermined pressures.
 5. The apparatus according to claim 1 ,wherein said housings include at least one of an optics space containingmembers of an optical system and a drive space containing drivingmembers.
 6. The apparatus according to claim 2 , wherein said housingsinclude at least one of an optics space containing members of an opticalsystem and a drive space containing driving members.
 7. The apparatusaccording to claim 5 , wherein said optics space is at least one of aguiding optics space for introducing exposing light from a light sourceinto the apparatus, an illuminating optics space for illuminating areticle with the exposing light, and a projection optics space forprojecting the reticle pattern onto the substrate.
 8. The apparatusaccording to claim 6 , wherein said optics space is at least one of aguiding optics space for introducing exposing light from a light sourceinto the apparatus, an illuminating optics space for illuminating areticle with the exposing light, and a projection optics space forprojecting the reticle pattern onto the substrate.
 9. The apparatusaccording to claim 5 , wherein said drive space is at least one of areticle-stage space containing a reticle stage on which the reticle ismounted, a substrate-stage space containing a substrate stage on whichthe substrate is mounted, and a masking-blade space containing a maskingblade.
 10. The apparatus according to claim 6 , wherein said drive spaceis at least one of a reticle-stage space containing a reticle stage onwhich the reticle is mounted, a substrate-stage space containing asubstrate stage on which the substrate is mounted, and a masking-bladespace containing a masking blade.
 11. The apparatus according to claim 5, wherein said optics space is a helium atmosphere and said drive spaceis a nitrogen-gas atmosphere.
 12. The apparatus according to claim 6 ,wherein said optics space is a helium atmosphere and said drive space isa nitrogen-gas atmosphere.
 13. The apparatus according to claim 7 ,wherein said control unit performs control in such a manner thatpressure within said projection optics space is held constant.
 14. Theapparatus according to claim 8 , wherein said control unit performscontrol in such a manner that pressure within said projection opticsspace is held constant.
 15. The apparatus according to claim 1 , whereinwhichever of said spaces requires a high level of cleanliness is held ata pressure higher than the pressures of the other spaces.
 16. Theapparatus according to claim 2 , wherein whichever of said spacesrequires a high level of cleanliness is held at a pressure higher thanthe pressures of the other spaces.
 17. The apparatus according to claim3 , wherein each of said air conditioners has a control valve forcontrolling a ratio of amount of purging gas supplied to amount ofexhaust, and pressure within a corresponding housing is regulated bysaid control valve.
 18. The apparatus according to claim 4 , whereineach of said air conditioners has a control valve for controlling aratio of amount of purging gas supplied to amount of exhaust, andpressure within a corresponding housing is regulated by said controlvalve.
 19. The apparatus according to claim 1 , wherein said controlunit controls the pressure within each of said housings in such a mannerthat amount of deformation of said members due to a differentialpressure between pressures within adjacent ones of said housings fallswithin a range in which said differential pressure has no significanteffect upon optical performance.
 20. The apparatus according to claim 2, wherein said control unit controls the pressure within each of saidhousings in such a manner that amount of deformation of said members dueto a differential pressure between pressures within adjacent ones ofsaid housings falls within a range in which said differential pressurehas no significant effect upon optical performance.
 21. The apparatusaccording to claim 1 , wherein a laser light source for said exposureapparatus is an F₂ excimer laser source.
 22. The apparatus according toclaim 1 , wherein a laser light source for said exposure apparatus is anF₂ excimer laser source.
 23. The apparatus according to claim 1 ,wherein the purging gas is an inert gas.
 24. The apparatus according toclaim 1 , wherein the purging gas is an inert gas.
 25. A method ofmanufacturing semiconductor devices, comprising steps of: placing aplurality of items of semiconductor manufacturing equipment, inclusiveof an exposure apparatus, in a semiconductor manufacturing plant; andmanufacturing a semiconductor device using said plurality of items ofsemiconductor manufacturing equipment; said exposure apparatus having: aplurality of housings, said housings are provided adjacently, whichcover at least part of an optical path of exposing light; memberstransparent to exposing light provided at boundaries of the adjacenthousings; a gas supplier which supplies the interior of each housingwith a purging gas; pressure sensors which sense pressures insiderespective ones of said housings; and a control unit which controls saidgas supplier on the basis of outputs from said pressure sensors in sucha manner that pressures within the respective housings will attainrespective ones of predetermined pressures.
 26. A method ofmanufacturing semiconductor devices, comprising steps of: placing aplurality of items of semiconductor manufacturing equipment, inclusiveof an exposure apparatus, in a semiconductor manufacturing plant; andmanufacturing a semiconductor device using said plurality of items ofsemiconductor manufacturing equipment; said exposure apparatus having: aplurality of housings, said housing are provided adjacently, which coverat least part of an optical path of exposing light; members transparentto exposing light provided at boundaries of the adjacent housings; a gassupplier which supplies the interior of each housing with a purging gas;differential-pressure sensors which sense differences in pressurebetween adjacent ones of said housings; and a control unit whichcontrols said gas supplier on the basis of outputs from saiddifferential-pressure sensors in such a manner that pressures within therespective housings will attain respective ones of predeterminedpressures.
 27. The method according to claim 25 , further comprising thesteps of: connecting said plurality of items of semiconductormanufacturing equipment by a local-area network; connecting saidlocal-area network and an external network outside the plant; acquiringinformation concerning said exposure apparatus from a database on theexternal network utilizing said local-area network and said externalnetwork; and controlling said exposure apparatus based upon theinformation acquired. predetermined pressures.
 28. The method accordingto claim 25 , further comprising the steps of: connecting said pluralityof items of semiconductor manufacturing equipment by a local-areanetwork; connecting said local-area network and an external networkoutside the plant; acquiring information concerning said exposureapparatus from a database on the external network utilizing saidlocal-area network and said external network; and controlling saidexposure apparatus based upon the information acquired.
 29. The methodaccording to claim 25 , wherein maintenance information for saidmanufacturing equipment is obtained by accessing, by data communicationvia the external network, a database provided by a vendor or user ofsaid exposure apparatus, or production management is performed by datacommunication with a semiconductor manufacturing plant other than thefirst mentioned semiconductor manufacturing plant via the externalnetwork.
 30. The method according to claim 26 , wherein maintenanceinformation for said manufacturing equipment is obtained by accessing,by data communication via the external network, a database provided by avendor or user of said exposure apparatus, or production management isperformed by data communication with a semiconductor manufacturing plantother than the first mentioned semiconductor manufacturing plant via theexternal network.
 31. A semiconductor manufacturing plant capable ofcommunicating, by data communication, information relating to at leastone item of semiconductor manufacturing equipment among a group thereof,said plant comprising: a plurality of items of semiconductormanufacturing equipment inclusive of an exposure apparatus; a local-areanetwork which interconnects said plurality of items of semiconductormanufacturing equipment; and a gateway which connects said local-areanetwork and an external network outside said semiconductor manufacturingplant; wherein said exposure apparatus has: a plurality of housings,said housings are provided adjacently, which cover at least part of anoptical path of exposing light; members transparent to exposing lightprovided at boundaries of the adjacent housings; a gas supplier whichsupplies the interior of each housing with a purging gas; pressuresensors which sense pressures inside respective ones of said housings;and a control unit which controls said gas supplier on the basis ofoutputs from said pressure sensors in such a manner that pressureswithin the respective housings will attain respective ones ofpredetermined pressures.
 32. A semiconductor manufacturing plant capableof communicating, by data communication, information relating to atleast one item of semiconductor manufacturing equipment among a groupthereof, said plant comprising: a plurality of items of semiconductormanufacturing equipment inclusive of an exposure apparatus; a local-areanetwork which interconnects said plurality of items of semiconductormanufacturing equipment; and a gateway which connects said local-areanetwork and an external network outside said semiconductor manufacturingplant; wherein said exposure apparatus has: a plurality of housings,said housing are provided adjacently, which covers at least part of anoptical path of exposing light; members transparent to exposing lightprovided at boundaries of the adjacent housings; a gas supplier whichsupplies the interior of each housing with a purging gas;differential-pressure sensors which sense differences in pressurebetween adjacent ones of said housings; and a control unit whichcontrols said gas supplier on the basis of outputs from saiddifferential-pressure sensors in such a manner that pressures within therespective housings will attain respective ones of predeterminedpressures.
 33. A method of maintaining an exposure apparatus, comprisingthe steps of: preparing a database, which stores information relating tomaintenance of said exposure apparatus, on an external network outside aplant at which said exposure apparatus has been installed; connectingsaid exposure apparatus to a local-area network inside said plant; andmaintaining said exposure apparatus, based upon information that hasbeen stored in said database, utilizing said external network and saidlocal-area network; wherein said exposure apparatus has: a plurality ofhousings, said housing are provided adjacently, which cover at leastpart of an optical path of exposing light; members transparent toexposing light provided at boundaries of the adjacent housings; a gassupplier which supplies the interior of each housing with a purging gas;pressure sensors which sense pressures inside respective ones of saidhousings; and a control unit which controls said gas supplier on thebasis of outputs from said pressure sensors in such a manner thatpressures within the respective housings will attain respective ones ofpredetermined pressures.
 34. A method of maintaining an exposureapparatus, comprising the steps of: preparing a database, which storesinformation relating to maintenance of said exposure apparatus, on anexternal network outside a plant at which said exposure apparatus hasbeen installed; connecting said exposure apparatus to a local-areanetwork inside said plant; and maintaining said exposure apparatus,based upon information that has been stored in said database, utilizingsaid external network and said local-area network; wherein said exposureapparatus has: a plurality of housings, said housings are providedadjacently, which cover at least part of an optical path of exposinglight; members transparent to exposing light provided at boundaries ofthe adjacent housings; a gas supplier which supplies the interior ofeach housing with a purging gas; differential-pressure sensors whichsense differences in pressure between adjacent ones of said housings;and a control unit which controls said gas supplier on the basis ofoutputs from said differential-pressure sensors in such a manner thatpressures within the respective housings will attain respective ones ofpredetermined pressures.
 35. An exposure apparatus capable of performingdata communication via a computer network, comprising: a networkinterface, which is connected to the network, for performing datacommunication, a display which displays results of the datacommunication; and a computer, which is connected to the network, forexecuting software for communicating data; said exposure apparatusfurther comprising: a plurality of housings, said housings are providedadjacently, which cover at least part of an optical path of exposinglight; members transparent to exposing light provided at boundaries ofthe adjacent housings; a gas supplier which supplies the interior ofeach housing with a purging gas; pressure sensors which sense pressuresinside respective ones of said housings; and a control unit whichcontrols said gas supplier on the basis of outputs from said pressuresensors in such a manner that pressures within the respective housingswill attain respective ones of predetermined pressures.
 36. An exposureapparatus capable of performing data communication via a computernetwork, comprising: a network interface, which is connected to thenetwork, for performing data communication, a display which displaysresults of the data communication, and a computer, which is connected tothe network, for executing software for communicating data; saidexposure apparatus further comprising: a plurality of housings, saidhousings are provided adjacently, which cover at least part of anoptical path of exposing light; members transparent to exposing lightprovided at boundaries of the adjacent housings; a gas supplier whichsupplies the interior of each housing with a purging gas;differential-pressure sensors which sense differences in pressurebetween adjacent ones of said housings; and a control unit whichcontrols said gas supplier on the basis of outputs from saiddifferential-pressure sensors in such a manner that pressures within therespective housings will attain respective ones of predeterminedpressures.
 37. The apparatus according to claim 35 , wherein the networksoftware provides said display with a user interface for accessing amaintenance database, which is connected to an external network of aplant at which said exposure apparatus has been installed, and which isprovided by a vendor or user of the exposure apparatus, thereby makingit possible to obtain information from said database via said externalnetwork.
 38. The apparatus according to claim 36 , wherein the networksoftware provides said display with a user interface for accessing amaintenance database, which is connected to an external network of aplant at which said exposure apparatus has been installed, and which isprovided by a vendor or user of the exposure apparatus, thereby makingit possible to obtain information from said database via said externalnetwork.